Electric speedometer



May 23, 1939. E G, KELLY y 2,159,330

ELECTRIC SPEEDOMETER Filed March 3, 1957 3 Sheets-Sheet l Muay 23, 1939.E Q KELLY 2,159,330

ELECTRIC SPEEDOUETER Filed March 3, 1937 3 sheets-sheet 2 May 23, 1939.E KELLY 2,159,330V l mLEcTRIc sPEnDouETER Filed March 3, 1937 3Sheets-Sheet 3 40 containing the operativeparts of the mechanism atedactuating means i2 and the latterv to the Patented May 23,1939 l l2,159,330

A AuNuren srATEs iwrlnvr oFFicE ELECTRIC sPEEDoMETEn Edward GeorgeKelly, Chicago, Ill., assignorfto s Stewart-Warner Corporation, Chicago,lll., a corporation of Virginia Application March `3, 1937, Serial No.v128,754

11 claims. (o1. 1v1-95) The present invention relates to electric speed-Fig.- 4 is a longitudinal verticaia-ction taken on ometers andparticularly toimprovements in the the line 4--4 of Fig. 3; constructionof the component parts thereof, Fig. 5 is a partial irregular verticalsection whereby the speedometer unit may be manutaken on the line 5-51ofFig. 4;

5 factured cheaply and assembled in a simple, in- Fig. 6 is a partialirregular vertical section 5 expensive manner. The invention is animprovetaken on the line 6--6 of Fig. 4; ment on the electricspeedometer construction Fig. 'l is perspective view of an insulatindisclosed in application Serial No. '15i,522, led spacer used in theconstruction of the mechanism November 23, 1934. l with parts thereofspaced apart -for thev purpose l The primary object of this invention isto proof better showing the construction; and 10 vide a new and improvedspeed indicating mech- Fig. 8 is a partial cross sectional view of amodianism that-can be easily and cheaply manufaciied form of armatureconstruction. -tured. Referringrst to Fig. l of the drawings, there Afurther object of the invention is to provide: is shown an electricallyoperated speed indicatl a new and improved speed indicating mechanisming system forming no part of the present invenl5 vthat is rugged andreliable in operation and one tion, but disclosed and claimed in thecopending i that can be readily calibrated and adjustedii7 applicationof Horace M. Norman, Serial No. i, it'should get out of adjustment forany reason 127,845, illed February 26, 1937.

whatever. The system comprises a speed indicating arm A further objectof the invention is to provide iii adapted to be moved by anelectromagnetical- 20 a new and improved speed indicator mechanism lyoperated actuating means i2, the position oi y that can be assembledreadily at the factory and which is controlled by a magneticallyoperated pnethat can be just as readily disassembled in current varyingmeans iii suitably driven from n case repairs are necessary after use. Ia gear it rotating in unison with a part, such (A still further objectis to'provide a new and as a rear wheel, oi a vehicle. 25 improvedsupporting means ior that member of The various elements of theapparatus are in-q the mechanism, in this case the armature, whichdicatecl as being connected in circuit with theA is actuated to aposition determined by the speed ignition system of an automobile.Energy is supof the vehicle. plied to the apparatus iromthe usualautomobile Another object of the invention is to provide Ibattery iiiunder the control of an ignition switch 'a new and improved supportingmeans for the 2t, shown in its open position, to which one tervsolenoidsadapted to actuate the armature memmina] of the battery is connected byafconductor ber of the mechanism. 22. The other terminal of the batteryis ground Another object of the invention is to provide ed to the frameas indicated at 24.

readily adjustable supporting means for these The ignition switch itilis connected by a con- 35 Solenoids whereby they may be Simultaneouslyductor 26 to one end of a ballast resistance 2B, adjusted from theloutside of the casing adapted the other end of which has connectedthereto a to house the mechanism. pair of branch conductors 3i? and 32,the former .Another object is to provide a compact unit of which leadsto the electromagnetically operand the various electrical resistorsforming part magnetically operated current varying means i4. oftheelectrical system. The ballast resistance itis made of any suitvOther objects and advantages oi the present able material having a highpositive temperature 5 invention Will appeal from th ensuing deSorllJ-jcoeiiicient of resistance. Thus when the battery tion of an embodimentof the invention in which Vonage is 10W, the initial current lowingrthrough reference iS had lio tho a@ooilllafl'ylflg..ClFMIHESd theresistance is low and the resistance is relain which: i y y tively cooland permits a predetermined value of Fis. 1 isa diagrammatic layout ofthe Speedcurrent to now through the indicating apparatus.

foineter indicating the various elements thereof g However, whenthebattery vgltage is high, the 50 'andlfllolr electrical lelationshpi sinitial currentfio is relatively high and the re'- Flg. 2 iS partialfront plan VlBW Ol the spedsistanc'the belast resistanceincreases,there-4 4ometer showing the face of the speed indicator; "by tending tomaintain the current flow constant Fig. 3 is atop plan view, partiallyin section, at said predetermined value.

'I 55 [of the .speed indicator operating mechanism; i', The actuating'means l2 comprises a. unitary 55 compensating resistors 46 and 48.

extending tapered portions 36 and 38 actuated by electromagnetic means,such as solenoids 46 and 42, respectively. The specic form of thearmature, which will be described more fully hereinafter, forms no partof the present inven-4 tion, but is the invention of Willard H. Farr andGeorge E. Coxon, and forms the subject/matter of a copending applicationSerial No. 128,734, filed March 3, 1937.

Solenoids 40 and 42 are connected in series with each other by aconductor 44 and have interposed in series therewith resistors v46 and48, respectively. Resistors 46 andy 48 have negative temperaturecoefficients of resistance and resistance values proportioned tocompensate for changes in the resistance of solenoids 40 and 42 causedby changes in temperatura of the solenoids resulting from variations incurrent iow therethrough. The circuit including they solenoids andcompensating resistors in series is connected by the previouslymentioned branch conductor 36 to the ballast resistance and throughconductor 58 to ground. l

The branch conductor 32 is connected to one end of a resistance 52, theother end of which is connected lto ground through conductor 54 and thepreviously mentioned conductor 50. It is seen, therefore, thatlconductors'32 and 54 connect the resistance 52 in parallel with theseries circuit including the solenoids 48 and 42 and the Associated withresistance 52 is a movable contact`56 connected by conductor 58 toconductor 44 and the position of which is controlled by the magneticallyoperated actuating means I4 in such are magnetically dragged by thepermanentl magnet to positions dependent upon the rate of rotation ofthe magnet and, therefore, also dependent' upon the speed of thevehicle. l The electric speedometer also comprises a milef age indicator62 which may be of the usual drum type. This indicator is driven througha spring 'biased pawl 64 actuated by an electromagnet 66,

one terminal of which is connected to the battery through conductor 68and ignition switch 20. 'I'he other terminal of the electromagnet isconnected.

by a conductor 10 to a normally open cam actuated switch 12 adapted tobe closed at predetermined \distance intervals by a suitable mechanismdriven by the previously described gear I6 rotating in unison with apart of the vehicle.' The switch 'I2 is connected to groundv through acontheoperation of therabove described electrical speedometer.

^' When the automobile is in motion, the switch 20 vabout to bedescribed ,crescent-shaped armature 34 having oppositely is normallyclosed, thereby establishing an electrical circuit through the threepreviously described parallel circuits, including the solenoids 48 and42, the xed resistance 52, and the magnet 66, respectively. 'Ihe gear I6rotates in Aunison withthe vehicle wheels and drives the magnet shaft60, which in turn rotates the magnet. The rotating eld created by themagnet tends to rotate the rotor to which the movable contact 56 isconnected in the same direction as the magnet, and the strength of thistendency is directly proportional to the speed of rotation of themagnet. Thus, the movable contact 56 assumes positions which at alltimes correspond to the speed of rotation of the magnet and, therefore,to the speed of travel of the vehicle.

When the movable contact 56 is located centrally of the `resistance 52,no current passes through the bridge circuit consisting of the movablecontact and conductor 58, and consequently the same current passesthrough. both solenoids 48 and 42 and the resistances 46 and 48, whichare in series with solenoids 48 and 42 respectively. Each of th'esesolenoids attrac s its associated portion of the armature with t e sameforce, and the pointer I8 indicates a speed corresponding toapproximately half the ultimate speed of the vehicle, or 44 miles anhour, 'as shown in the drawings.

When the speed of the vehicle is such that the movable contact 56 ismoved toward one end of the resistance 52, a greater current passesthrough one of the solenoids than through the other. The solenoidreceiving the strongest current exerts the greatest forcel upon itsassociated armature and draws a large/r cross sectional part thereofinto the solenoid, at the same time withdrawing the other armatureportion from its associated solenoid.

This movement of the armature portions and the pointer shaft continuesuntil the shifting compensates for the dierence in solenoid currents,whereupon the pointer shaft and pointer come to rst and indicatel thespeed of the vehicle, which corresponds to the particularrelationship ofthe. solenoid currents then existing. Y

The negative temperature coefiicient resisances 46 and 48 maintain theresistance of the res ective branch circuits in which they are placedconstant at all times, so that changes in temperature of the solenoids40 and 42 are prevented from creating errors in the reading of thespeedometer.

-The construction of the speed indicating means e shown particularly inFigs. 3 toA 6, inclusive. The indicang means comprises an integralsupporting structure or vframe 88 comprising-a substantially annularfront support 82'and a rear support 84 connected by a pair oflongitudinal vertically spaced apart upper and lower arms 86 and 88,respectively. The rear support 84 comprises three radially extendingarms 90, 92 and 94. provided with threaded open? ingsi whereby the rearsupport may be attached to a suitable part 36 of the vehicle by screwbolts 98.

From Fig. 5y it maybe seen thattheupper horizontal arm 86 is formedintegral with the upper junction of the radial arms 88 and 82,-and thatthe .lowerhorizontal arm 88 is formed integral with the lower andvertically extending radial arm 94.

The front support 82 is provided with a forward extending projection |00upon which is mounted a cup-shapedfmember |82 secured thereto by boltsi114. In this cup-shaped member is located a dial v plate |06 attachedto the cup-shaped member by of the vehicle.

bolts |08 and provided with suitable indicia. as shown in Fig. 2. Thecup-shaped member is suitably secured to a portion, such as thedashboard The pointer cooperates with the indicia on dial plate |06 andis secured to a shaft ||0 mounted for rotation on a horizontal axis. Theshaft is journaled' intermediate its ends in a relatively narrowvertically vextending strip or web |f|2 secured to the projectingportion |00 of the front end of support 80, between the latter andcupshaped member |02, by the previously mentioned screw bolts |04. Therear end ofthe shaft is journaled in a horizontally disposed V-shapedbracket |4 formed integrally with the front support and extendingsubstantially midway between the upper and lower arms 86 and 80 to nearthe center of these arms. The bracket |4 is provided with a bearing ||6in which the -end of the shaft rotates with a minimum of friction.

Movement is transmitted to the indicator shaft from actuating means tobe described more fully hereinafter by a vertically disposed circularbevel gear |.I8 mounted on shaft ||0 adjacent the bracketend thereof,and in order to prevent vibrations and road shocks from deleteriouslyaffecting the indicating unit, an inertia wheel |20 is frictionallymounted on the shaft.

The inertia wheel is mounted adjacent the front bearing por-tion of theshaft ||0 on an enlargement |22 fixedly secured to the lshaft H0 andprovided with an integral circular flange |24 against which abuts anannular sleeve |26 to which the inertia wheel is attached. The'inertiawheel-is held against longitudinal movement by a washer |28 lsecured inabutting relation to the sleeve |26 on the enlargement |22.

When the vehicle is atrest, the indicating shaft and the hereinafter tobe described actuating unit are returned to their zero positions Vby aspiral spring |30 having one end suitably secured to shaft ||0intermediate the shaft supporty H2 and the indicating dial |06.` Theother end of the spring is secured. to a forwardly extending flange |32punched out cf a plate |34 adjustably mounted o'n the vertical shaftsupport 2 by means of slots |36 formed thereon at opposite sides of theshaft and through which extend securing bolts |38. The actuating unit,by means of which the indicator shaft H0 is rotatedcomprises a pair ofsolenoids 40 and 42 through the central openings of which extend thetapered armature portions 36 and 38. respectively. The armature 34 ismounted substantially centrally thereof on a right-angled support |40xedly secured to a shaft |42 mounted for rotation on a vertical axis inremovable bearing members |44 'and |46 carried by the, upper and lowerhorizontal arms 86 and 88, respectively. The right-angled support |40also carries a substantially sector-shaped bevel gear |48 of smalldiameter adapted to engage the circular bevel gear ||8 when ltheindicating unit is secured to the integral 'support 80 by screws |04.

The construction of the sector-shaped bevel gear |48 with av relativelysmall diameter and extending shaft ||0 to near the center of the unit sothat the `gear |46 may engage gear H8,

f the vertical shaft |42 is mounted, comprise jeweled thrust bearingportions |50 and guide sleeves |52. The bearing members are firmly heldin adjusted position on outwardly extending substantially circularbosses |54 and 1|56 by cap screws`|58. l l

The armature support |40 comprises a horizontally extending relativelynarrow strip |60 secured to a hub |62 attached to, shaft |42 at a pointbelow the V-shaped bracket ||4 andthe lower horizontal arm 88. Thepreviously mentioned sector gear |48 is secured t'o the horizontal stripby suitable means, such as the rivet |64. A downwardly'dependingthreaded weight |66 in which is rotatably mounted an adjusting screw |68is 4also secured to the horizontal strip. The purpose of the weight andadjusting screw is to provide a means of balancing the weight of thearmature member 34 so that no side thrust is imposed on the bearingssupporting shaft |42. In this inanner binding caused by unevendistribution of weight about the shaft |42 is avoided.

The vertically extending portion |10 of the right-angled support |40extends upward to a point between the V-shaped bracket |4 and theupperhorizcntal arm 86. At its upper end it is provided with ahorizontally extending, ange |12 to which the central portier! of thecrescent- .shaped armature 34 is secured by means of bolts In order toreduce eddy currents and hysteresis loss to a minimum, the armature 34is constructed of a plurality of thin sheets of carefully selected softiron. These sheets are held together by rivets |16 and the bolts |14'.

Substantially centrally of the crescent-shaped armature'34 there isprovided a brass filler plate |80 for the purpose of increasing thereluctance of the magnetic power through the armature so that thearmature will not be drawn beyond predetermined limits by either 'of thesolenoids 40 or 42. As previously stated, a solenoid when supplied withincreasing amounts of current draws a portion of the armature having agreater cross' sectional area into the central portion of the solenoid.By providing the armature with a central portion having a greaterreluctance, it'is seen that the movement of the amature by either of thesolenoids is limited, and the armature cannot be drawn into the solenoidpast the portion of increased reluctance.`

A modified form of construction of the arrangesectional area of thearmature at the central part thereof. cross section of the armaturesufciently large so that the magnetic saturation of the iron never risesabove the rectilinear portion of the B-H curve. With armatures of suchlarge cross sections, lag is eliminated and more accurate reading ofinstruments is obtained.

From Fig. 3, in particular, it may be seen that the armature 34 extendssubstantially around the vertically extending shaft |42. The taperedportions 36 and 38 thereof extend into the central openings of thesolenoids 40 and 42. These solenoids are supported on opposite sides ofthe upper horizontal arm 86 by means of integral metallic strips |82 and|84 adjustably mounted on the upper arm 86. The supporting strips |82and |84 are provided with similar bent end portions |86 substantiallyencircling the lateral sides It is desirable also to make thed ofthesolenoids and supporting them in such manner that the armature isreadily movable through the central hollow openings therein.

'Ihe ll'ent portions |86 are also provided with relatively narrowfingers |88 adapted to be bent radially inward to hold securely thesolenoids,

as clearly illustrated in Fig. 5. The solenoid is f insulated from theencircling supporting strips by an annular insulating strip |90 yplacedbetween` the solenoid and the bent portions. |86, and a novel insulatingspool |92 constructed of 'two sep,-

arate intertting portions |94 and 96, as illus-V trated in Fig. 7. Eachportion of the spool comprises a'central longitudinal member |98provided with a flanged portion 288 coextensive in length therewith andextending substantially at rightv vinto opposite cutawayl portions -228and 222 formed on the flanges 284. The longitudinal flanges 288 areprovided with opposite projections 224 adapted to llt into cutawayportions 226 formed on the longitudinal central portions |98, wherebythe two portions are brought into predetermined spaced relationship whenassembled. It may be seen that the construction affords a very simpleand economical arrangement for supporting the solenoids' and insulatingthem from the surrounding supporting strips.

As previously stated, the solenoid supporting strips 82 and |84-aremounted adjustably upon theupper horizontal arm 86. The supportingstrips |82 and |84 are providedwith substantially semi-circular enlargedends 238 and 2,32, respectively. These are provided with centralopenings 234' surrounding the boss |54 formed on the upper h rizontalarm 86, and are provided with oppositely disposed arcuate slots 236through which extend screw bolts 238, whereby the strips may be securelyheld in adjusted position. Lock washersA 248 may be utilized to preventany undesired rotation of the strips. l

The solenoids .are adapted to be simultaneously rotated in the samedirection around boss |54 by means of a horizontally disposed toothedwheel 242 rotatably secured on the upper side of the horlzontalfarm 86by ascrew bolt 2431. The

wheel,242 His provided with teeth 244 adapted to engage coinciding teeth246 and 248 formed on' the semi-circular portions 230 and 232 of thesolenoid mounting strips |82 and |84, respectively. l

From Fig. 3 it may be notedl that only a relative1y few teeth oreprovided o xthe toothed portions of the respective members, but it isobvious that the number and-size may be changed as de-` sired in orderto obtain proper movement of the solenoids. From Fig. 3 it is furtherevident that rotation of the toothedwheel 242 results in rotation ofboth the solenoids in the same direction,"

so that when adjustment of the solenoids is desired, it is necessaryonly to rotate the wheel 242.

The supporting structure 80, that has been described in detail above, isnot only adapted vto carry the described indicator and actuating units,

B ut also to support e part of the electrical apperatus used in,the'system illustrated in Fig. l.

. The electrical apparatus is supported .on a cupances 46 and 48 aresecured to the support side D of the insulating cup 250 by meansofspji'inv clips, .258 land 268 secured to substantially .tria gularinsulating plates 262 and'264 mounted on the insulating cup `by means ofbolts 266 and 268, re-

spectively. Bolts 266 and 268 extend through the base at points equallydistant from the center of the support and near the points where theradially extending arms 90, 92 and 94 converge. 'Ihis arrangementprovides a very compact assembly by reason that the supporting means andthe resistance units are located in a-very narrow compass.

The bolts 266 and 268 also form terminals leading to parts of theelectrical circuit illustrated in Fig. 1. 'I'he base plate 258 isprovided also with a third terminal-bolt 218 leading to another part ofthe electrical circuit. Bolt 210 extends through the base plate into anopening 21| on` the rear portion of the support and is, therefore,insulated from thev latter. The bolts are secured to the base plate bynuts 212 spaced from the base plate by a circular insulating disc 214.The ballast resistance 28 is secured across terminal vbolts 218 and 268by means of nuts 216 and is From a comparison of the construction ofFig. C

4 with the electrical system of Fig. l, it may be seen that the terminal218 is connected to conductor 26, terminal'268 to the branch conductors32 and 30, while the remaining terminal 266is connected to conductor 58.Thus, the speed indicating means is a complete unit in itself and may bemounted in a desirable location in the vehicle at a considerabledistance from the magnetically operated current varying means I4'.

In the assembly of the described unit, the supporting structure is rstpreferably cast and machined; then the base plate 258 and the actuatingunit secured thereto. Thereafter the indieating unit comprising thecup-shapedv member |82 is mounted on1the `supporting means, and the unitis complete for use wherever desired. Each of the above subunits may bemanufactured independently and thereafter assembled to form a completespeed indicating unit as described above.

If `it is found necessary torepair the speed in- ||8. Furthermore, theremoval of the dial platel z permits adjustment of the spring carryingplate I 3l.

The electrical apparatus included in the unit is likewise easilyremovable. 'Ihe solenoids may -be removed simply by loosening bolts 238vand manually rotating armature 34 to a position where the coils may beslipped between the ends thereof. The resistances are all` separatelyremovable.

I claim:

1. In apparatus of the type described, the combination including anactuating unit and an indicating unit detachably secured thereto, saidactuating unit comprising a pair of horizontally l disposed supportingarms and a shaft mounted between said arms for rotation on a verticalaxis, raid indicatingl unit comprising supporting means and a shaftmounted thereon for rotation on a horizontal axis,`and.movementtransmitting means mounted on each shaft adapted to interengage when theunits are secured in place, said transmitting means being so constructedand arranged that the weight thereof is concentrated near the axis ofsaid first mentioned shaft.

2. In apparatus of thetype described, the combination including anactuating unit and an indicating unitldetachably secured thereto, saidactuating unit comprising a pair of horizontally7 disposed supportingarms and a shaft mounted between said arms for rotation on a verticalaxis, said indicating unit comprising supporting means and a shaftmounted thereon for rotation on` a horizontal axis, and movementtransmitting means mounted on each shaft adapted to interengage when theunits are secured in place, said transmitting means comprising a smalldiameter sector gear secured for rotation with said rst mentioned shaftand a cooperatively associated gear mounted on said second mentionedshaft.

3. In apparatus of the type described, the combination includingindicating means, a shaft mounted for rotation on a horizontal axis foractuating said means, a shaft mounted for rotation on a vertical axis,means including an electromagnetically actuated armature for impartingrotation to said second mentioned shaft, said armature substantiallysurrounding said shaft mounted for rotation on a horizontal axis foractuating said means, a shaft mounted for rotation on a verticalaxisfmeans including an electromagnetically actuated armature for'imparting rotation to said second mentioned shaft, saidarmaturesubstantially surrounding said shaft and 'being secured theretoby a right angle support,

. the portion of the support secured to the shaft being substantiallyparallel to and spaced from the armature by the portion of the supportextending at right angles therefrom parallel to the axis of rotation ofthe shaft, gear means located .between the armature and support carriedby said support, and cooperatively associated gear means mounted on saidrst mentioned shaft adapted to be rotated by said first mentioned.

gear means when the second mentioned shaft is rotated.

5. In apparatus of the type described, the combination including asupporting structure comprising a pair of horizontal oppositelydisposedarms and a horizontally disposed substantially V- shaped bracket locatedbetween said arms and extending from one end of said structure to nearthe center of said arms, an indicating unit detachably secured to saidstructure comprising a horizontally vdisposed shaftn supported by aportion of said unit and by the bracket, an actuating unit comprising ashaft mounted `centrally of and between said arms for rotation on avertical axis, an electromagnetically actuated armature substantiallysurrounding said shaft and located between said bracket and the upperone of said arns, supporting means for said armature secured to saidshaft between said bracket and the lower one of said arms, and means fortransmitting movement from one shaft to the other.

6. In apparatus of the type described, the combination including asupporting structure comprising a pair of horizontal oppositely disposedarms and a horizontally disposed. substantially V-shaped bracket locatedbetween sa'd arms and extending from one end of said struc ure to nearthe center of said arms, an indicating unit detachably secured to saidstructure comprising a horizontally disposed shaft supported by aportion of said u nit and by the bracket, an actuating unit comprising ashaft mounted centrally of andl between said arms for rotation on avertical axis, an electromagnetically actuated armature substantiallysurrounding said shaft and located between said bracket and the upperone of said arms, horizontally disposed supporting means for saidarmature secured to said shaft between said bracket and the lower one ofsaid arms and means for transmitting movement from one shaft to theother, said means including a sector gear mounted onthe upper side ofsaid supporting means and a gear secured to the horizontally disposedshaft adjacent the bracket endthereof adapted to be engaged by saidsector gear when the indicating unit is secured to said structure. l

7. In apparatus o f the type described, the combination including asupporting structure comprising a pair of horizontal oppositely disposedarms and a horizontally disposed substantially Vfshaped bracket locatedbetween said arms and extending from one end of said structure to nearthe center of said arms, an indicating unit detachably secured to saidstructure at the bracket supporting end -comprising a horizontallydisposed shaft supported by a portion of said unit and the bracket, anactuating unit comprising a shaft mounted centrally ofand between saidarms for rotationon a vertical axis, an electromagnetically actuatedarmature substantially surrounding said shaft and located between saiding means for said armature secured to said shaft between said bracketand the lower one of said arms, means for transmitting motion from oneshaft to the other, and inertia means frietionally mounted on said rstmentioned shaft between said bracket and the supporting portion of theindicating unit.

8. In apparatus of the type described, the com- 'bracket and the upperone of said arms, support- Y bination including a supporting structurecomprising a pair of horizontal oppositely disposed arms and ahorizontally disposed substantially V-shaped bracket located betweensaid arms and extending from one end of said structure to near thecenter of said arms, an indicating unit de'- tachably secured to saidstructure at the bracket supporting end comprising a horizontallydisposed shaft supported by a portion of said unit and the bracket, anactuating unit comprising a shaft lmounted centrally of and between saidarms for rotation on a vertical axis, an electromagnetically actuatedarmature suhstantiaiiy surrounding said shaft and located between said lbracket and the upper one of said arms, supporting means for saidarmature comprising a horizontal portion secured to said shaft betweensaid bracket and the lower one of said arms, means for transmittingmotion fromone shaft to the other, said means including a sector gearmount- .ed on the upper side of the horizontal portion of saidsupporting means, and a circular gear secured to the horizontallydisposed shaft adjacent the bracket end thereof adapted to be engagedAbysaid sector gear when the indicating gear is arms and extending fromone end of said structure to near the center of said arms, an indicatingunit detachably secured to said structure at the bracket supporting endcornprising a vertically extending support vand a horizontally disposedindicator operating shaft supported thereby, and by the bracket, anactuating unit comprising a shaft mounted centrally of and between saidarms for rotation on a vertical axis, anelectromagnetically actuatedarmature substantially surrounding said shaft and located between saidbracket and the upper one of said arms, supporting means for saidarmature secured to said shaft between said bracket and the lower one ofsaid' arms, means for transmitting motion from one shaft to the other,and

spring means secured atone end to said horizontally .disposed shaft andat the other end to said vertically extending support for biasing saidshafts to a zero position.

10. In apparatus of the type described, the

combination including a supporting structure comprising a pair ofhorizontal oppositely` disposed arms and a horizontally disposedsubstantially V-shapedbracket located between said arms and extendingfrom one end of said stmoture tonear the center of said arms, anindicating unit detachably secured to said structure at the bracketsupporting end comprising a vertically lextending support and ahorizontally disposed indicator operating shaft supported thereby and bythe bracket, an actuating unit comprising a shaft mounted centrally ofand between said arms for rotation on a vertical axis, anelectromagnetically actuated armature substantially surrounding saidshaft and located between said bracket and the upper one of said arms,supporting means for said armature having a horizontal portion securedto said shaft between said bracket and the 'lower one ofsaid arms, meansfor transmitting motion from one shaft to the other, said meansincluding a sector gear mounted on the upper side of the horizontal lportion of said supporting means, anda circular gear secured to thehorizontally disposed shaft' posed shaft between said circular gear andthe yvertically extending portion,-` and means including a plateadjustably mounted on said vertically f armature, the combinationincluding a support and a substantially rigid fstllp of metallicmaterial secured to said support for supporting said solenoid, saidstrip being provided with an end portion bent substantially to encirclesaid solenoid. I

12. In electric apparatus utilizing an armature and a pair of solenoidsfor actuating said armature, the combination including a support, a pairof substantially rigid oppositely disposed metallic strips for securingsaid solenoids lto said support, said stripsbeing provided with endportions bent substantially to encircle said solenoids, and projo/tionsadapted to be bent atan angle to said encircling portions for furthersecuring said'solenoids.

13. In electric apparatus utilizing an armature and a pair of solenoidsfor. actuating said armature, the combination including a support, apair of oppositely disposed rotatably mounted arms r for securing saidsolenoids to said support, said port.' in cooperative relation to saidtoothed por.

tions, and means permitting rotation of said wheel for simultaneouslyrotating both-arms.

15. In electrical indicating apparatus of the type described includingelectromagnetic actuating means and resistors in circuit therewith, `aunitary support for said .actuating meansl and resistors, including incombination, a substantially circular support of vinsulating material, asupport for said electromagnetic actuating means and. circular `supportcomprising a structure pr-'l vided with three radially extending arms,and

substantially triangular supports fitting between said radiallyextending arms for securing said resistors to said circular support.

16. An insulating spool for a solenoid includinga pair of complementarysections, each including a longitudinal portion provided with a rightvangled flange extending the'length thereof forming the body of the spooland ends for said spool comprising substantially semi-circular flangesextendiig at rightangles to'said body portion.

17. An insulating spool for a solenoid including a pair of complementaryintertting sections, each comprising a longitudinal portion,` a flangedportion coextensive in length therewith, said flanged portions havingfingers extending into grooves formed on said longitudinal portions, andends for said spool comprising end flanges extending at right angles tosaid longitudinal and first mentioned flanged portions, each of saidvendflanges being provided with projecting portions tting into similarcut-away portions on the other. i EDWARD GEORGE KELLY.

